The invention is directed to a process for the production of 1-amino-2-mercapto-2-methylpropyl phosphonic acid or 1-amino-2-mercapto-2-methylpropyl alkyl phosphinic acids. These compounds are pharmaceutically active materials, especially suitable for the treatment of inflammations, degenerative diseases of the joints such as rheumatoid arthritis and Wilson's illness.
It is known to produce 1-amino-2-mercapto propyl phosphonic and phosphinic acids by reacting thiazolines-(3), in a given case as the hydrochloride, at elevated temperature in the molten condition or in the presence of a solvent with phosphonic acid (phosphorous acid) or a phosphinic acid and subsequently splitting the thiazolidine ring (EPO published application No. 33919, the entire disclosure of which is hereby incorporated by reference and relied upon). The disadvantage of the process especially is that the yields are only about 30%.